Fan test device

ABSTRACT

A fan test device is connected to an interface of a fan under test on a motherboard. The fan test device includes a connector, a power test unit, a signal test unit, a single chip microcontroller (SCM), and a keyboard. The power test unit includes a first contact and a second contact. The first contact is connected to a ground pin of the connector. The second contact is connected to a power pin of the connector. The signal test unit includes a third contact and a fourth contact. The third contact is connected to the first contact. The fourth contact is connected to a pulse width modulation (PWM) signal pin of the connector. The keyboard is connected to the SCM to input a max speed and a preset duty cycle of the fan.

BACKGROUND

1. Technical Field

The present disclosure relates to a fan test device.

2. Description of Related Art

An interface of a fan on a motherboard includes four pins. During a fan signal integrity test, users will use a test rod having a probe that directly contacts a ground pin of the interface. Because there is minute distance between a power pin and the ground pin, the probe of the test rod may contact the power pin and the ground pin at the same time, which would cause damage to the motherboard. During a fan test, a pulse width modulation (PWM) signal of the fan should be tested under different duty cycles. Typically, adjusting the duty cycles needs to modify data of a register, which is complicated.

Therefore, there is room for improvement in the art.

BRIEF DESCRIPTION OF THE DRAWING

Many aspects of the present disclosure can be better understood with reference to the following drawing(s). The components in the drawing(s) are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawing(s), like reference numerals designate corresponding parts throughout the several views.

The figure is a block diagram of an embodiment of a fan test device of the present disclosure.

DETAILED DESCRIPTION

The figure shows an embodiment of a fan test device 10 of the present disclosure.

The fan test device 10 includes a connector 101, a power test unit 102, a signal test unit 103, a single chip microcontroller (SCM) 104, a first display 105, a second display 106, and a keyboard 107. The first display 105 is used to display a duty cycle. The second 106 is used to display speed.

The connector 101 includes a ground pin 201, a power pin 202, a speed signal pin 203, and a pulse width modulation (PWM) signal pin 204. The connector 101 is connected to an interface 40 of a fan 30 under test on a motherboard 20.

The power test unit 102 includes a first contact 205 and a second contact 206. The first contact 205 is connected to the ground pin 201 of the connector 101. The second contact 206 is connected to the power pin 202 of the connector 101.

The signal test unit 103 includes a third contact 207 and a fourth contact 208. The third contact 207 is connected to the first contact 205. Thus, the third contact 207 is electrically connected to the ground pin 201 of the connector 101. The fourth contact 208 is connected to the PWM signal pin 204.

The SCM 104 is connected to both of the speed signal pin 203 and the PWM signal pin 204. The SCM 104 is also connected to the first display 105 and the second display 106.

The keyboard 107 is connected to the SCM 104.

During a test, the connector 101 is connected to the interface 40 of the fan 30. A ground pin and a power pin of the interface 40 are connected to the ground pin 201 and the power pin 202, respectively. Therefore, first contact 205 and the second contact 206 are electrically connected to the ground pin and the power pin of the interface 40, respectively. Space between the first contact 205 and the second contact 206 is large enough to enable easy and accurate connection.

In this embodiment, a max speed FMAX and a preset duty cycle P1 of the fan 30 is input to the SCM 104 through the keyboard 107. According to a formula: F1=FMAX*P1, a speed F1 of the fan 30 can be obtained. The SCM 104 outputs a first control signal to the speed signal pin 203 to control the fan 30 to operate under the speed F1.

Typically, an actual speed signal of an actual speed F2 of the fan 30 is output to a baseboard management controller (BMC) 22 of the motherboard 40 by the fan 30. The BMC 22 receives the actual speed signal and gets the actual speed F2 of the fan 30. An actual duty cycle P2 of the fan 30 can be calculated: P2=F2/FMAX. The BMC 22 outputs a PWM signal for the actual duty cycle P2 to the PWM signal pin 204. The fourth contact 208 is electrically connected to the PWM signal pin 204. A duty cycle P of the PWM signal could be calculated according to P=P2/P1.

The duty cycle P of the PWM signal is output to the first display 105 to be displayed. The first display 105 is also used to display the preset duty cycle P1. The second display 106 is used to display the speed F1.

While the disclosure has been described by way of example and in terms of preferred embodiment, it is to be understood that the disclosure is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the range of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. 

What is claimed is:
 1. A fan test device, comprising; a connector used to connect an interface of a fan under test on a motherboard, the connector comprising a ground pin, a power pin, a speed signal pin, and a pulse width modulation (PWM) signal pin; a power test unit comprising a first contact and a second contact, wherein the first contact is connected to the ground pin of the connector, the second contact is connected to the power pin of the connector; a signal test unit comprising a third contact and a fourth contact, wherein the third contact is connected to the first contact, the fourth contact is connected to the PWM signal pin of the connector; a single chip microcontroller (SCM) connected to the speed signal pin and the fourth contact; and a keyboard connected to the SCM to input a max speed FMAX and a preset duty cycle P1 of the fan, according to a formula: speed F1=FMAX*P1; the SCM outputs a first control signal to the speed signal pin to control the fan to operate under the speed F1, the fan outputs an actual speed F2 of the fan to a baseboard management controller (BMC) of the motherboard; an actual duty cycle P2 of the fan is calculated according to a formula: P2=F2/FMAX, the BMC outputs a PWM signal for the actual duty cycle P2 to the PWM signal pin, and a duty cycle P of the PWM signal is calculated according to a formula: P=P2/P1.
 2. The fan test device of claim 1, further comprising a first display connected to the SCM to display the actual duty cycle P2 and the preset duty cycle P1.
 3. The fan test device of claim 1, further comprising a second display connected to the SCM to display the speed F1. 